(a)      If a person timely files, the person may apply to intervene in a proceeding before the Commission.

      (b)      The Commission shall grant leave to intervene unless the Commission concludes that:

            (1)      the parties to the proceeding adequately represent the interest of the person seeking to intervene; or

            (2)      the issues that the person seeks to raise are irrelevant or immaterial.

      (c)      (1)      An intervenor has all the rights of a party to a proceeding.

            (2)      In a proceeding before the Commission, an individual who is an intervenor may represent himself or herself.